Grinding, " diesel " noise under valve covers

Dig that. I'm just concerned that too much advance could cause this? Does sound like p.s. pump. But in both valve covers? Did the washer shim trick. No leaks. But, I HAVE NOT checked the fluid. Car has been parked due to dizzy issues. Just rebuilt front end, so I have to get her to an (Hahaha!) Alignment ( sick joke) shop....built the 340.12 years ago, nothing has changed except the car, ignition,.and the 66 had really loud pipes. So it could have been there all the time. ...